The present invention relates generally to an apparatus and method for producing and aligning components for forming a combined filter tipped cigarette without the use of a combining machine. More particularly, this invention relates to an apparatus and method for aligning the elements of a combined filter and a wrapped tobacco rod, closing gaps between the elements, and then wrapping the filter and a portion of the tobacco rod with tipping paper.
Cigarettes typically comprise a wrapped tobacco rod that optionally is tipped with a filter. The tobacco rod comprises tobacco or other filler material such as tobacco substitutes, stems, or reconstituted tobacco which has been cut, shredded, extruded or otherwise prepared for incorporation in a tobacco product. The filter typically is either a plain filter (without charcoal) or a combination charcoal filter. Two types of combination charcoal filters are cavity fill filters and combined filters. A cavity fill filter has combining paper wrapped around spaced apart plain filter elements (typically having an acetate base material) with charcoal pieces in the gaps.
A combined charcoal filter has several filter elements, one being a segment of charcoal filter, which generally is a plain filter with carbon interspersed in the base material, the other being a segment of plain filter.
It is known to manufacture cigarettes having combined filters using a double-wrap process. In a double-wrap process, the combined filter is manufactured and wrapped first and then a second operation is performed to combine the filter and tobacco rod using tipping paper. More specifically, the plain and charcoal filter elements are fixed together with combining paper and are joined to the wrapped tobacco rod with tipping paper that is wrapped around a portion of the wrapped tobacco rod and the entire filter.
A single-wrap process, such as that taught in Okumoto U.S. Pat. No. 4,867,734, also is known. In the single-wrap process, unwrapped filter components and tobacco rod components are aligned next to each other. Typically, double and triple length components are fed to processing drums, cut and then spread apart. Additional filter components then are introduced between the cut and separated components. The added components generally must be spaced apart from the cut components, typically by gaps of 5 mm or more, in order to allow for manufacturing tolerances.
The gaps between the aligned components are closed either by (a) blowing the components closer together using an air stream; (b) using a series of compressing drums to close the gaps; or (c) using a swash ring drum to push the components together. A wrapped tobacco rod is placed at each end of the aligned filter elements and tipping paper is wrapped around the filter elements and a portion of the wrapped tobacco rod. A typical arrangement of combined charcoal filter tipped cigarettes has, arranged in series from the tip, a plain filter element, a charcoal filter element, and a wrapped tobacco rod.
The known double-wrap process possesses an number of known disadvantages. One such disadvantage is that separate machines are required to (1) join the plain and charcoal filter elements with combining paper, and (2) place the charcoal filter in alignment with the wrapped tobacco rod. It is a further disadvantage of the double-wrap process that separate machines occupy floor space and can result in increased machine maintenance and lost production time.
Another disadvantage of the double-wrap process is that at least two layers of paper are required to form filter tipped cigarettes.
The known single-wrap process also possesses a number of known disadvantages. One such disadvantage is that the spacing required between components to meet manufacturing tolerances results in a large total gap between the components during manufacturing.
Another disadvantage is that the gaps must be closed in order to join the wrapped tobacco rod to the filter.
A further disadvantage of the single-wrap process is that known processing drums for closing gaps can only move a limited distance. Typically, several processing drums are required in series in order to close the gaps.
A disadvantage of using compressed air to blow the cigarette components to close gaps is that a slow drum speed must be used to avoid overcoming the vacuum force holding the components to the drums. Typically the drum speed is limited to conveying 2000 cigarettes per minute.
A further disadvantage of blowing to close gaps is that the movement of the components produces friction which may damage the components.
Yet another disadvantage is that a source of pressurized air must be provided.